So I was listening to music at very high volumes just now, not sure how high as I don't have an SPL meter to confirm. But I noticed the speakers started to lose some grip. I could probably call it compression.

The RX6 speakers I have have a 200W power handling figure. My integrated amp can supply about 75W. My question is, can speakers compress even if the power is significantly lower than their power handling limits?

Monitor Audio state recommended power between 60-200W.

Or was this a function of my amplifier possibly clipping? I know speakers are mechanically and thermally limited, but would this be a thermal limitation, or a mechanical limitation?

There are several things at issue here. First, the continuous power of your amplifier does not tell you what it can do at peaks. Second, there are pretty much no standards for power ratings for speakers, and many are rated for what it will take to destroy them, not for what they can handle and still sound good.

So, there is no telling, just from what you have told us, whether the distortion is from the amplifier, the speakers, or both. If you tried a significantly more powerful amplifier, you could then try the same volume and see if you get the same distortion. If you did, then it would mean that the speakers are distorting now, and if you didn't get any distortion, it would mean that it was the amplifier. If you got some distortion, but less than before, it would mean both your amplifier and your speakers are causing your current distortion.

Also, different speakers are dramatically different on this issue. I had a pair of speakers a long time ago that seemed to gradually distort more and more as the volume increased, but had another pair that seemed fine, until all of a sudden the woofer would "bottom out," of course causing massive distortion. (I kept the second of these, and sold the first.)

I can say one thing for sure, and that is that if you are hearing much distortion, you should turn the volume down, as you have pretty much reached the safe limits of your gear.

God willing, we will prevail in peace and freedom from fear and in true health through the purity and essence of our natural fluids. God bless you all.

I'm just trying to understand if I'm amp limited or speaker limited. Is it possible for a speaker to mechanically compress the sound even if the applied power is well below the rated power handling figure from the manufactures?

So if a speaker has a power handling figure of 300 watts and I am using a 50 watt amplifier, if I turn the volume to very high levels, is it possible for the speaker to distort as a function of mechanical distortion and not due to insufficient power?

I'm just trying to understand if I'm amp limited or speaker limited. Is it possible for a speaker to mechanically compress the sound even if the applied power is well below the rated power handling figure from the manufactures?

So if a speaker has a power handling figure of 300 watts and I am using a 50 watt amplifier, if I turn the volume to very high levels, is it possible for the speaker to distort as a function of mechanical distortion and not due to insufficient power?

Yes and yes. However, what is possible, and what is actually happening, need not be the same thing.

Think about it. You have a speaker. To make our lives simple, think of a cone woofer. If you push on it, it is easier to move it at first, but the closer you get to the maximum it can go, the harder it is to push for each additional millimeter. That harder to move is going to compress the sound. This, by the way, is one of the reasons that some people love things like Klipschorns, because they are capable of extremely high volume, no sane use of them in an ordinary home is going to be coming close to the limits of how loud the speakers can do. This is why some people describe them as having "effortless" dynamics. It is because no sane use of them ever really approaches the limits of their maximum volume. In my own view, I would much rather have something different (Magnepan is more my style), but I can appreciate the virtues of a speaker like a Klipshorn even though it is not my ideal.

You might also want to reread my previous post on how different different speakers can react to increased power. Some (at least subjectively; I did not measure my speakers to know what was really going on) gradually increase the distortion as one increases the volume, whereas others have a more sudden onset of distortion as the volume increases.

God willing, we will prevail in peace and freedom from fear and in true health through the purity and essence of our natural fluids. God bless you all.

Just want to understand this better. If I use a speaker that has a power handling of 200W (claimed) and I use an amp of 50W, it's possible to cause mechanical distress from the speaker even though I did not push the thermal limits of the speaker?

If a speaker is mechanically limited then I assume no amount of extra power will help. But one can't have a speaker that is mechanically stressed because not enough power was supplied?

I think it is pretty fanciful to ask for diagnostic help without having any objective data to share at all.

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But I noticed the speakers started to lose some grip. I could probably call it compression.

It could be just the ears shutting down because of high SPLs. It could be lots of things.

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The RX6 speakers I have have a 200W power handling figure. My integrated amp can supply about 75W. My question is, can speakers compress even if the power is significantly lower than their power handling limits?

Of course. People complain about power amp spec sheets, but most of them are encyclopedias of reliable information compared to speaker spec sheets.

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Monitor Audio state recommended power between 60-200W.

That and $2.00 might get you a cup of coffee in a cheap coffee shop ;-)

This is probably the best and most complete set of information that relates to your question, and it says almost nothing about volume compression in those speakers:

Just want to understand this better. If I use a speaker that has a power handling of 200W (claimed) and I use an amp of 50W, it's possible to cause mechanical distress from the speaker even though I did not push the thermal limits of the speaker?

Yes.

Most speakers are measured at 90 dB SPL, and with a few ragazines that want to be extra complete, the extra robust speakers might get another shot of measurements at 95 dB SPL.

For the average speaker 90 dB SPL takes 1.00 watts, and 95 dB SPL takes more like 4.00 watts. There are usually measureable differences in performance between those two power levels.

50 watts or 200 watts are over there in the next universe! ;-)

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If a speaker is mechanically limited then I assume no amount of extra power will help.

But one can't have a speaker that is mechanically stressed because not enough power was supplied?

A speaker being mechanically overstressed because not enough power was supplied makes as much sense as a 200 MPH car being overstressed by driving 100 mph.

Think about it. You have a speaker. To make our lives simple, think of a cone woofer. If you push on it, it is easier to move it at first, but the closer you get to the maximum it can go, the harder it is to push for each additional millimeter.

Actually, there is no problem with having to push harder for each additional millimeter. This is how a perfectly linear spring works.

Trouble is that speaker suspensions are far from being perfectly linear springs.

I think it is pretty fanciful to ask for diagnostic help without having any objective data to share at all.

It is also fanciful to expect objective data from unknown instruments. Do you actually own and can vouch for the reliability and performance of this device? I assume not and that this is just a search you did on ebay. If so, please state it that way. These things are junk. They are sold under many brands all with the same "specs." You have no idea what guts it comes with, how reliable it is, what frequency response it has, etc. Here is a review from a similar "40 to 130 db" SPL meter on Amazon: http://www.amazon.com/40-130-Digital-Decibel-Pressure-Logger/dp/B004VUQU0E

"a complete waste of money
By Jeremy on April 3, 2012
What a piece of s***. We bought this thing so we could document the noise our douchebag neighbor was making. When it arrived, we tested it twice and it seemed okay. But when we turned it on for the third time, when our douchebag neighbor was actually making noise, it failed to turn on. Basically, it broke within 2 weeks of arrival. Don't buy this piece of junk."

It is one thing to tell people to buy the cheapest audio gear they can but entirely different matter when it comes to instruments. You can eat fast food everyday to save money but the day you have a heart problem, you don't want to go shopping for the cheapest surgeon on the web to operate on you!

Thank heavens Heinrich was smart enough to ignore your suggestion and bought a branded meter. These things will last you a lifetime so get a good one.

Think about it. You have a speaker. To make our lives simple, think of a cone woofer. If you push on it, it is easier to move it at first, but the closer you get to the maximum it can go, the harder it is to push for each additional millimeter.

Actually, there is no problem with having to push harder for each additional millimeter. This is how a perfectly linear spring works.

Trouble is that speaker suspensions are far from being perfectly linear springs.

A real world speaker is far less linear than that. It might take 3 pounds to deflect by 2 mm, and that might be a pretty good speaker.

You should see the bad ones! ;-)

You have the quotes a bit wrong, as you have what I stated attributed to Heinrich S. But please look a bit closer at what I wrote. I did not merely state that it was harder to push it further, but that the amount one had to push extra for each additional millimeter was more than before. I can see, though, that what I wrote could have been clearer than it was. In other words, we are in perfect agreement about the difficulty involved in pushing a cone further and further.

God willing, we will prevail in peace and freedom from fear and in true health through the purity and essence of our natural fluids. God bless you all.

Most speakers are measured at 90 dB SPL, and with a few ragazines that want to be extra complete, the extra robust speakers might get another shot of measurements at 95 dB SPL.

For the average speaker 90 dB SPL takes 1.00 watts, and 95 dB SPL takes more like 4.00 watts. There are usually measureable differences in performance between those two power levels.

50 watts or 200 watts are over there in the next universe! ;-)
A speaker being mechanically overstressed because not enough power was supplied makes as much sense as a 200 MPH car being overstressed by driving 100 mph.

But that's the thing. What causes mechanical stress? So you are saying that a speaker with a power handling of 200W can distort with a 70W amp mechanically and not thermally? Wouldn't the amp be clipping in order to push the speaker into mechanical distortion?

Wouldn't mechanical stress be caused by low and loud bass signals? If the issue is in the mids, upper mids or highs, wouldn't it be thermal related, as in I'm not using enough?

Most speakers are measured at 90 dB SPL, and with a few ragazines that want to be extra complete, the extra robust speakers might get another shot of measurements at 95 dB SPL.

For the average speaker 90 dB SPL takes 1.00 watts, and 95 dB SPL takes more like 4.00 watts. There are usually measureable differences in performance between those two power levels.

50 watts or 200 watts are over there in the next universe! ;-)
A speaker being mechanically overstressed because not enough power was supplied makes as much sense as a 200 MPH car being overstressed by driving 100 mph.

But that's the thing. What causes mechanical stress?

The two strongest sources of physical stress in speakers is diaphragm displacement and heat build up in the voice coil.

The performance fundamentals are that in order to survice and sound good the diaphragm has to be able to travel back and forth in a linear fashion, and the voice coil has to dissipate heat.

The heat problem is there because the thermodynamic efficiency of most home speakers is around 1% or so. 99% oor so of the amplifier's power that is actually fabricated and delivered to the speaker gets turned into heat and about 1% gets turned into sound. If we look at very large price and size is no object professional speakers, the efficiency is about 10 dB or about 3 times greater. In either case the lack of efficiency is appalling, but its the best we can do right now or have been able to do since Lee DeForest and the turn of the previous century.

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So you are saying that a speaker with a power handling of 200W can distort with a 70W amp mechanically and not thermally?

No, the distortion is due to both mechanical and thermal issues.

Tweeter voice coils are tiny and yet they may havve to dissipate a lot of heat for their size. They have to be made out of copper or aluminum or something like them and these materials experience very significant changes in resistance due to normal heating and cooling as they operate. You apply a lot of power to a tweeter, its voice coil resistance might double, and less current than is expected is able to flow through it even though more voltage is applied to it. Voila! Thermal compression.

As I mentioned earlier, a speaker diaphragm has to move in a mechanically linear fashion to have linear response at all relevant SPL levels, but the physics of cone suspensions and magnetic motors fight against this. Linear diaphragm travel is an issue with woofers, midranges and tweeters near the bottom of their frequency range.

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Wouldn't the amp be clipping in order to push the speaker into mechanical distortion?

Not necessarily. Please recall the power levels I mentioned in an earlier post - 1 watt and 4 watts. Most speakers are producing or verging on producing say 1% THD or more over part of their operational frequency range by the time amplifier power reaches 4 watts. Distortion in speakers does not follow the same pattern as amplifiers. Instead of being low and then spiking up at the clipping point, their distortion rises more slowly. That means more distortion at lower levels.

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Wouldn't mechanical stress be caused by low and loud bass signals? If the issue is in the mids, upper mids or highs, wouldn't it be thermal related, as in I'm not using enough?

I see evidence of mechanically produced distortion at the low end of the operational frequency range of even very expensive and relatively good speakers:

This is the measured THD performance of the Paradigm Studio 100 V3 @ a mere 95 dB SPL:

I saw a table of speaker distortion at various spl levels and frequencies. By the time it hit 92 dB, distortion in the sub bass region was approaching 10% for the particular set of speakers - the make was not shown. Higher frequency distortion was still well under 3%. At that sort of SPL, typically an amp will only be idling along at well under 5W where THD will still be very low. I can only imagine that pushing the volume up will further increase speaker distortion in that region while the amp's THD will still be well under 1%

Thing is, based on the specs, my speaker can play LOUD plus it can handle a lot of power based on the power handling figure.

I lack that confidence since I see no information about nonlinear distortion versus SPL. The speaker might be able to crank out 112 dB SPL, but how clean are they? I strongly suspect that at 28 Hz and 110 dB the THD is on the order of 10% or more. Actually, I seriously doubt that this speaker can generate 110 dB @ 28 Hz at all. At 400 Hz, different story.

To generate 28 Hz @ 110 dB clealy takes something like a very heavily built 12-15" subwoofer, and the biggest driver in the RX6 is a 6", and that is like 1/4 the cone area or less and 1/3 the Xmax or less, for a total of 1/12 or less of the air moving ability.

Furthermore, subwoofer drivers don't generally do well at frequencies that are much above 200 Hz, and the RX6 operates its woofer up to 700 Hz, so its no subwoofer!

I saw a table of speaker distortion at various spl levels and frequencies. By the time it hit 92 dB, distortion in the sub bass region was approaching 10% for the particular set of speakers - the make was not shown. Higher frequency distortion was still well under 3%. At that sort of SPL, typically an amp will only be idling along at well under 5W where THD will still be very low. I can only imagine that pushing the volume up will further increase speaker distortion in that region while the amp's THD will still be well under 1%

"The non-linearity of the ear has been known over a century, but it was relatively recent that the OHC of the cochlea were identified as the primary cause. The middle ear is quite linear over sound pressures of 40 to 110 dB SPL, and does not result in noticeable distortion at normal listening levels (Hartmann page 512). The inner ear non-linearity does produce distortion, which can be heard, and measured in the ear canal. In fact, the measurement of distortion products in the ear canal is used as a hearing test for newborn infants, since the distortion products are absent for certain forms of hearing impairment!
"

So he says that the middle ear (the boney part and the ear drum) is quite linear, but he also says that the Outer Hair Cells in the cochlea are the primary cause of the distortion.

I'm a little familiar with the kinds of measurements that he is describing - I been taught by and talked at length with technical specialists who work with them and are familiar with the science behind them. They are based on the fact that the ear produces so much distortion that the distortion products are measurable in the air in the pinnea and outer ear. The source of the distortion is buried inside the head and it can be readily detected on the outside. It's contaminating the entire ear!

I'm thinking that if I had a microphone that worked this poorly, it would be out of here! But with our ears, we have no alternatives at this time.

Originally Posted by ärnyk
So he says that the middle ear (the boney part and the ear drum) is quite linear, but he also says that the Outer Hair Cells in the cochlea are the primary cause of the distortion.

But I don't see where he said primary? He just said that the inner ear non-linearity does produce distortion, which can be heard, and measured in the ear canal. Not that it was the primary cause or anything. Did I miss something?

Originally Posted by ärnyk
So he says that the middle ear (the boney part and the ear drum) is quite linear, but he also says that the Outer Hair Cells in the cochlea are the primary cause of the distortion.

But I don't see where he said primary?

Look again, I cut-and-pasted the text including the word primary from the web site you linked. ;-)

So that means that if I'm mechanically limited then it would be at low frequencies [of each of the drivers as previously mentioned]. If I'm thermally limited then it would be at mids and highs only? Mainly because of the size of the parts involved; woofer voice coils are larger, and can tolerate and dissipate more heat than the comparably fragile vc in mids and tweets

Look again, I cut-and-pasted the text including the word primary from the web site you linked. ;-)

It said the OHC iof the cochlea s the primary cause of distortion. So then what about the middle ear? It says from 40 to 110 dB SPL that the middle ear is quite linear, and does not result in noticeable distortion at normal listening levels. How do these two things relate? Further it says the inner ear non-linearity does produce distortion, which can be heard, and measured in the ear canal. Is that the OHC?

Basically what I'm trying to say is, if you don't listen to music at 110 dB, for peaks, it's not going to cause in-ear distortion according to what they say about the middle ear.

Originally Posted by Wayne Highwood
So that means that if I'm mechanically limited then it would be at low frequencies [of each of the drivers as previously mentioned].

What do you mean for the rest of the drivers?

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If I'm thermally limited then it would be at mids and highs only? Mainly because of the size of the parts involved; woofer voice coils are larger, and can tolerate and dissipate more heat than the comparably fragile vc in mids and tweets

But mechanically the mids and highs can tolerate higher SPL than the lows can? If the sound started to compress in the mids, upper bass at very high volumes, then it would be more likely for it to be amplifier clipping than the speaker mechnically distorting?

I asked a colleague at work the same question who knows a thing or two as well. He says he doubts a 75W amp will drive a pair of speakers to much distortion with a power handling of 200W, but that amp clipping is more likely to be at fault during dynamic sequences. As always, I'd love to hear if my thinking is off.

Thing is, based on the specs, my speaker can play LOUD plus it can handle a lot of power based on the power handling figure.

The thing is, based on the specs, you have absolutely no idea how much distortion they will have at any power input. So, in answer to your original question, it is very, very possible to have high levels of distortion well below a 200 watt input.

Very likely, the 200 watts means that it can handle that power (briefly) without being destroyed. That does not tell you how soon you will be having massive amounts of distortion that you will find annoying.

God willing, we will prevail in peace and freedom from fear and in true health through the purity and essence of our natural fluids. God bless you all.